Korea Research Institute of Chemical Technology

Daewoong Pharmaceutical Co., Ltd.

Daewoong Bio Inc.

Kwang Joo Kim

Chul Ung Kim

Beom Sik Kim

Jung Min Lee

Choong Kyun Yeom

Hye Jin Kim

Yong Kim

Jung-Min Lee

Sang Jin Moon

Soo Jin Choi

Jae Cheon Koh

Byung Goo Lee

Seong Soo Oh

Hang Kyo Jin

Sang Bong Oh

Won Uook So

The present invention relates to novel Forms A, B, C, D, E, F and G of crystalline 9-[2-[phosphonomethoxy]ethyl]adenine bis-pivaloyloxymethyl ester, i.e., adefovir dipivoxil, and processes for preparing them. According to the present invention, said novel crystal forms having a high purity can be obtained by a simple method and in a high yield.

Crystal forms of adefovir dipivoxil and processes for preparing the same

This invention relates to a method and apparatus for on-line measurement of permeation characteristics (transmitting chemicals) through dense nonporous membrane. This invention is intended to facilitate various research activities, such as simultaneous analyses of diffusion coefficient, solubility coefficient, permeation rate and permeant composition, and presentation of new analysis about the permeation behavior, kinetics and so on. The object of this invention is to provide the method and apparatus for measurement of permeation characteristics of permeants in liquid, vapor or gas phase through dense nonporous membrane and more practicuraly, to provide permeation apparatus for measurement of permeation characteristics by analyzing permeation rate and permeation concentration of permeants through an on-line type dense porous membrane with time, not only for a steady state but also for an unsteady state in an accurate and reliable manner.

Method and apparatus for on-line measurement of the permeation characteristics of a permeant through dense nonporous membrane

This invention relates to a polyion complex separation membrane with a double structure, which is applicable in the separation process of a water-soluble mixture having ionic molecules or particles by means of reverse osmotic pressure for the purposes of recovering expensive ionic organic materials such as anionic emulsifiers from the waste water. More particularly, this invention relates to said membrane having anionic polymers, as substrate, which is immersed into a cationic polymer solution containing a multivalent ion cross-linking agent, by which a cross-linkage within the internal of the separation membrane is achieved, thereby forming an ion complex between ionic polymers of opposite ion at the surface of the separation membrane to yield a stable separation membrane of a double structure.

Polyion complex separation membrane with a double structure

Process for preparing controlled-released chitosan microcapsule

Method for concentrating aqueous tetrafluoroethylene emulsion by

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Daejeon, South Korea

Kwang Joo Kim